Air conditioning device

ABSTRACT

An air conditioning device using a false ceiling ( 2 ) and ensuring air diffusion along walls by providing intake of treated air into a volume created by the gap between the ceiling ( 1 ), the sealed false ceiling ( 2 ) and the walls ( 3 ), comprising spacers ( 4 ) between the wall and the section ( 6 ) fixing on edge the false ceiling, of slight width parallel to the wall and uniformly spaced, the spacers, fixed on the wall or on the section fixing on edge the false ceiling, providing a gap between the wall and the false ceiling, so as to enable air diffusion over the entire periphery of the premises. The device is provided with one or several beads ( 7 ) clipped between the section and the wall so as to close the gap in the zones where air diffusion should be blocked.

[0001] This invention relates to a building air-conditioning device thatuses treated air that is admitted in a volume that is created betweenwalls, a ceiling and a sealed false ceiling, but that comprises a thinspace that is reserved over all or part of its periphery. This treatedair, after having cooled or heated the false ceiling, which in its turnradiates to the building, diffuses in the space between the wall and thefalse ceiling to ensure the remainder of the heating or cooling of thebuilding, as well as the mixing and the renewal of the air of thebuilding.

[0002] Air-conditioning processes by the ceiling that are dividedessentially into three categories are known:

[0003] So-called static processes, which in all cases require a renewalof the air by an independent ventilation system, and which in heatingmode ensure the increase in temperature of the false ceiling by electricheating films or hot water circulation, whereby this false ceiling thenensures the heating of the building by radiation, which exhibits thedrawback of an often excessive false ceiling temperature that interfereswith thermal comfort. These same processes, in cooling mode, usecirculating water, for example in coils, to cool the false ceiling(EP-A-0 552 690), which in its turn radiates to the building, whichexhibits the drawback of limiting the temperature of the false ceilingso as to prevent condensation problems and therefore to limit thecooling possibilities of such a system. Finally, these systems generallyoperate only in one of two modes, namely heating or cooling;

[0004] The processes by a blowing mixture of hot or cold air (U.S. Pat.No. 3,779,150) via nozzles, slots or linear diffusers that are placed inthe false ceiling that require a considerable speed of introduction ofthe treated air into the occupied volume. These processes bring about athermal discomfort of the occupants because of the air stream sensationsand because the air is not distributed uniformly in the building.

[0005] A process that uses a diffusion of air over all of a permeablefalse ceiling that has, both in heating mode and in cooling mode, goodperformance levels in terms of comfort, but that exhibit the drawback ofresulting in a quick fouling of the permeable ceiling.

[0006] Also known by DE-U-89 08 672 is a false ceiling attachment thatmakes possible the creation of a peripheral space for air passage for anair-conditioning installation, whereby this attachment is carried out,at regular intervals, by crosspieces. Such an embodiment does not makeit possible, however, to influence specifically the diffusion of airalong preferred paths.

[0007] Furthermore, U.S. Pat. No. 3,352,076 describes a false ceilingsection that is equipped with sealable openings that are placed atregular intervals over its length and that can be closed or open basedon requirements. However, this document does not describe a means thatmakes possible a flexible and careful control of a flow of air intodetermined locations along the walls.

[0008] This invention has as its object to remedy these drawbacks byproposing an air-conditioning device that makes it possible to improvethe diffusion of air in the building along the walls, while perfectlycontrolling its distribution. Below, air conditioning is defined as thecreation of an artificial climate in the proper building to establishexcellent conditions of comfort for the occupants.

[0009] For this purpose, the air-conditioning device that uses a falseceiling and that ensures a diffusion of air along the walls by allowingtreated air to enter in a volume created by the space between theceiling, the sealed false ceiling and the walls, which includescrosspieces between the wall and the edge rail of the false ceiling, ofa small width parallel to the wall and evenly spaced, whereby saidcrosspieces, attached to the wall or to the edge rail of the falseceiling, reserve a space between the wall and the false ceiling so as toallow the diffusion of air over the entire periphery of the building, ischaracterized in that it is equipped, in predetermined zones, with oneor several rods that are gripped between the rail and the wall so as toclose the space in the zones where it is desired to block the diffusionof the air.

[0010] The device according to the invention allows the air conditioningof a building by using a false ceiling and by ensuring a diffusion ofair along the walls. It allows treated air to enter in a volume that iscreated by the space between the ceiling, the sealed false ceiling andthe walls. The treated air can be new air or recycled air or a mixtureof the two: it can be filtered, set at a desired degree of humidity,cooled or heated. This treated air is introduced in the volume above thefalse ceiling by any suitable means such as one or more intake openingsmade in the wall between the ceiling and the false ceiling. This treatedair can also be produced by a fan-convector unit or a ceiling light boxthat is placed directly in the volume above the false ceiling if thespace between the false ceiling and the ceiling is adequate.

[0011] The device according to the invention comprises for this purposecrosspieces between the wall and the edge rail of the false ceiling, ofa small width parallel to the wall and evenly spaced. The false ceilingcan be made of a rigid material or consists of a sealed elastic membranestretched between the edge rails. Said crosspieces reserve a spacebetween the wall and the false ceiling and thus make possible thediffusion of the air over the entire periphery of the building. Thesecrosspieces are bolted, for example, to the walls or to the edge rail ofthe false ceiling and have a thickness perpendicular to the wall that iscalculated to obtain a determined diffusion rate of the treated air inthe building. The crosspieces can also be made in the mass of the edgerail if the latter is produced, for example, of plastic material in asingle injection-molding operation. The treated air, when it expands atvery low speed into the volume above the false ceiling, heats or coolsthe ceiling and the false ceiling that radiates in turn to the building.The air then diffuses along the walls outside of the occupied zone ofthe building at a temperature that is moderate and that ensures theremainder of heating or cooling, the mixing of the air of the buildingand, optionally, the renewal of air. Considerable comfort results fromthe device according to the invention because:

[0012] The heat load of the building is ensured in part by radiation andin part by circulation of air in the building,

[0013] The difference in temperature between the different walls and theair is thus reduced,

[0014] The air is diffused beyond the occupied zone of the building,

[0015] The air is diffused uniformly in the entire building.

[0016] According to a characteristic of the invention, the rods that aregripped between the rail and the wall can be full rods. It is alsopossible to produce these rods in the form of rods pierced with orificessuch as holes or slots. Thus, it is possible to prevent the diffusion ofthe air, for example in the vicinity of the recovery of the recycled airor the extraction of fouled air, which would bring about direct recoveryof the air without it circulating in the building.

[0017] According to a particular embodiment, so as to reduce the lossesof load of the air circulating in the space created between the ceilingand the false ceiling, the edge rail of the false ceiling comprises inits upper part a rounded shape on its upper ridge on the side of thewall, whereby the center of the curvature of this rounded shape isoriented toward the interior of the building.

[0018] In cooling mode, the air easily penetrates the building even ifits speed in the space reserved between the wall and the false ceilingis low because it is heavier than the ambient air. In contrast, inheating mode, it is necessary to increase this diffusion speed so as toforce this air to penetrate the building and to avoid the stratificationphenomenon. For this purpose, according to a particular embodiment, arod, whose thickness perpendicular to the wall is less than the distancebetween the wall and the wall-side face of the core of the edge rail, isgripped, for example, by the bottom, in the space between the edge railand the wall over the entire periphery or over a portion of theperiphery of the building. Narrow flexible blades that extend parallelto the wall and that are evenly spaced on the rod can allow, by a springeffect, the gripping of said rod.

[0019] The above-described solution exhibits the drawback of requiringthe placement and then the removal of said rod according to heating orcooling requirements. All of the particular embodiments described belowaim at eliminating this drawback by controlling the extent of closing ofthe space reserved between the wall and the edge rail, for example at apredetermined temperature at a certain level and in a certain locationin a building.

[0020] For this purpose, the edge rail is provided with a means thatallows a variable closing of the space reserved between the wall and theedge rail.

[0021] According to a particular embodiment, the means that makespossible a variable closing of the space reserved between the wall andthe edge rail comprises, on the one hand, a horizontal wing that isintegral with the edge rail on its upper part, and, on the other hand, asection called a closing strip that consists of a blade, parallel to theupper wing of the edge rail and above, extended from the wall side by arounded shape, whose center of the curvature is oriented toward theinterior of the building, whereby the end of the rounded shape on theside of the wall will just penetrate the space reserved between the walland the edge rail above the crosspieces by resting on the upper ridge onthe side of the wall of the edge rail, whereby said closing profile has,in addition, an L shape that produces a closed box between the curvedpart and the blade, whereby said closing strip is linked to the upperwing of the edge rail via a vertical blade that is located closer to thebuilding-side end than the upper ridge on the side of the wall of theedge rail, whereby this joint between said closing strip and thevertical blade is carried out by a zone of less thickness in its upperportion or by any other means. Also provided is a means that makes itpossible to actuate the rotation of the closing strip around the joint.In addition, blocks with less thickness perpendicular to the wall thanthe crosspieces, but with a width parallel to the wall that isessentially identical or equal to that of said crosspieces, can beplaced flush with the wall so as to limit the closing of the space.

[0022] According to another particular embodiment, coil springs or leafsprings, called retractile springs below, are placed at regularintervals, between the blade of the closing strip and the horizontalupper blade of the edge rail beside its building-side end, keeping theclosing strip abutting against the upper wall-side stop of the edgerail.

[0023] According to a particular embodiment, the means that makes itpossible to actuate the rotation of the closing strip around the jointconsists of evenly spaced electromagnets, mounted, thanks to a recessmade in the edge rail between the blade of the closing strip and theupper horizontal wing of the edge rail, close to the vertical blade thatmakes the connection between the edge rail and the closing strip butfrom the side of the wall. Said electromagnets are controlled at adistance either by a circuit breaker or by slaving to a temperaturesensor that is placed in the volume created by the space between theceiling and the sealed false ceiling and the walls. The action of saidelectromagnets causes the rotation of the closing strip around the jointwhen the building needs to be heated instead of cooled. If necessary,the return of the closing strip into its position that abuts against theblocks is carried out by the action of the retractile springs.

[0024] According to a particular embodiment, the means that makes itpossible to actuate the rotation of the closing strip around the jointconsists of reservoirs that contain wax, liquid or saturating vapor,so-called expansion bulbs of wax or liquid or saturating vapor, evenlyspaced and mounted thanks to a recess made in the edge rail between theblade of the closing strip and the horizontal wing of the edge railclose to the vertical blade that makes the connection between the edgerail and the closing strip and the side of the wall. In their upperpart, said bulbs comprise a piston or an elastic membrane or a bellowsthat actuates the rotation of the closing strip around the joint in caseof an increase in temperature, causing the expansion of the wax or ofthe liquid or the evaporation of a fluid that is located in said bulbs.

[0025] According to a particular embodiment, the means that makes itpossible to actuate the rotation of the closing strip around the jointconsists of U-shaped bimetallic strips that comprise two long horizontalwings that consist of two materials with very different expansioncoefficients that are integral with one another over their entiresurface. Said bimetallic strips are gripped at regular intervals inslots that are provided for this purpose in the blade of the closingstrip at the building-side end and in the upper horizontal wing of theedge rail at the building-side end, whereby said bimetallic strips aremade such that of the two materials of which they consist, the one thathas the higher expansion coefficient under the effect of a temperatureincrease is located on the outside face of the U that constitutes thebimetallic strip. Thus, in the case of an increase in temperature of theair that is located above the false ceiling, a proximity of the two endsof the bimetallic strips causes the lifting of the closing strip byrotation around the joint that is provided in the top of the verticalblade ensuring the connection between the edge rail and the closingstrip.

[0026] According to a particular embodiment, the means that allows avariable closing of the space reserved between the wall and the edgerail comprises a corrugated section that ends on the side of the wall bya rounded shape, whose end penetrates the space reserved between thewall and the edge rail and is attached by its other end to thebuilding-side end of the upper horizontal wing of the edge rail, wherebysaid corrugated section is, on its upper face, covered by and integralwith a sheet that consists of a material that has a lower thermalexpansion coefficient than the one of the material that constitutes thecorrugated section. Under the effect of a differential expansion of thetwo materials that constitute the corrugated section, there results,during an increase in temperature in the volume above the false ceiling,a more or less significant closing of the space reserved between thewall and the rail, a closing optionally limited by the blocks that arelocated above the crosspieces.

[0027] The accompanying drawings illustrate the invention:

[0028]FIG. 1 shows a top view of a cutaway in a horizontal plane of anair-conditioned building according to the invention.

[0029]FIG. 2 shows a sectional drawing AA in a vertical plane of anair-conditioned building according to the invention.

[0030]FIG. 3 shows a sectional drawing in a vertical plane perpendicularto the wall of the detail of the connection of the edge rail with thewall in the case where the false ceiling consists of a rigid material.

[0031]FIG. 4 shows a sectional drawing in a vertical plane that isperpendicular to the wall of the detail of the connection of the edgerail to the wall in the case where the false ceiling consists of astretched elastic membrane, whereby the shape of the edge rail of thestretched membrane is given by way of indication.

[0032]FIG. 5 shows a sectional drawing in a vertical plane that isperpendicular to the wall of a device that improves the invention.

[0033]FIG. 6 shows a sectional drawing in a vertical plane that isperpendicular to the wall of a device that improves the invention.

[0034]FIG. 7 shows a sectional drawing in a vertical plane that isperpendicular to the wall of a device that improves the invention.

[0035]FIG. 8 shows a sectional drawing in a vertical plane that isperpendicular to the wall of a device that improves the invention.

[0036]FIG. 9 shows a sectional drawing in a vertical plane that isperpendicular to the wall of a device that improves the invention.

[0037]FIG. 10 shows a sectional drawing in a vertical plane that isperpendicular to the wall of a device that improves the invention.

[0038]FIG. 11 shows a sectional drawing in a vertical plane that isperpendicular to the wall of a device that improves the invention.

[0039] In reference to these drawings, the device according to theinvention comprises crosspieces 4 between wall 3 and false ceiling 2 ofa small width parallel to the wall and evenly spaced. These crosspiecesthus reserve a space 5 between wall 3 and rail 6. This space makespossible diffusion over the entire periphery of the building of treatedair that is moderated after its passage into the false ceiling volumethat is created by the space between ceiling 1, sealed false ceiling 2and walls 3 because of the heat exchange of this air by convection withfalse ceiling 2 and ceiling 1. Said crosspieces 4 are bolted, forexample, to walls 3 or to edge rail 6 or directly integral with rail 6if the latter is made of a plastic material in a singleinjection-molding operation. These crosspieces have a thickness that isperpendicular to wall 3 that is calculated to obtain a diffusion rate ofthe treated air in the building with a fairly low rate of renewal.

[0040] According to the invention, the air-conditioning device isequipped, in predetermined zones, with one or more rods 7 that aregripped between rail 6 and wall 3 so as to close space 5 in the zoneswhere it is desired to block the diffusion of air.

[0041] According to a first embodiment of the invention, rods 7 that aregripped between rail 6 and wall 3 can be full rods. It is also possible,according to another embodiment of the invention, to produce these rods7 in the form of rods that are pierced with orifices such as holes orslots.

[0042] In the embodiment according to FIG. 6, edge rail 6 of the falseceiling comprises at its upper part a rounded shape 8, on its upperridge 15 on the side of the wall, whereby the center of the curvature ofthis rounded shape 8 is oriented toward the interior of the building.This rounded shape 8 has the advantage of facilitating the flow of airinto space 5 by reducing pressure drops there.

[0043] In the embodiment according to FIG. 7, a rod 9, whose thicknessperpendicular to wall 3 is less than the distance between wall 3 andface 35 that is beside the wall of the core of rail 6, is placed inspace 5 against face 35 of rail 6 or against the wall. This rod cancomprise on its wall-side face flexible blades 10 of a small widthextending parallel to the wall and spaced evenly on the rod, so as tocarry out, by a spring effect, its gripping in space 5 between rail 6and wall 3. This rod 9, placed over the entire periphery or over aportion of the periphery of the building, makes it possible to reducethe passage section of the treated air in space 5 so as to increase itsspeed and therefore to force the air downward in the building when thedevice operates in heating mode.

[0044] Edge rail 6 can be provided with a means that makes possible avariable closing of space 5 that is reserved between the wall and edgerail 6.

[0045]FIG. 8 shows a means that allows a variable closing of the spacereserved between the wall and the edge rail. Edge rail 6 comprises, onthe one hand, a horizontal wing 12 that is integral with rail 6 on itsupper part, and, on the other hand, a strip 20 that consists of a blade11, parallel to upper wing 12 of edge rail 6 and above, extended fromthe wall side by a rounded shape 13, whose center of the curvature isoriented toward the interior of the building, whereby end 14 of therounded shape on the side of the wall penetrates space 5 abovecrosspieces 4 by resting on upper ridge 15 on the side of the wall ofrail 6. This closing strip 20 has an L shape 33 that produces a closedbox between curved part 13 and blade 11 so as to make rigid said closingstrip 20 in bending. Whereby said closing strip 20 is linked to upperwing 12 of rail 6 via a vertical blade 16 that is located closer to theend on building side 17 than ridge 15, a joint between said strip 20 andvertical blade 16 can be carried out by a zone of less thickness 18 orby any other means. This device comprises a means that makes it possibleto actuate the rotation of strip 20 around joint 18. Blocks 19 areplaced flush with wall 3 and extend crosspieces 4 in their upper part;they have less thickness perpendicular to the wall than crosspieces 4but with a width parallel to the wall that is approximately identical orequal to that of crosspieces 4. Coil springs or leaf springs 21 thathave the function of retractile springs are placed at regular intervalsbetween blade 11 of strip 20 and wing 12 of rail 6 beside its end 17,keeping strip 20 abutting against stop 15 of rail 6.

[0046] A means that makes it possible to actuate the rotation of strip20 around joint 18 can consist of electromagnets 22, evenly spaced,mounted, thanks to a recess 36 made in rail 6, between blade 11 of strip20 and wing 12 of rail 6, close to vertical blade 16 of the wall side.Said electromagnets are controlled at a distance, either by a circuitbreaker or by slaving at a predetermined temperature in a certainlocation and at a certain level in a building. The action of saidelectromagnets causes the lifting of strip 20 when the building needs tobe heated instead of being cooled. The lifting to the level of theelectromagnet is scaled down by a lever effect due to the rotation ofstrip 20 around joint 18. This rotation of strip 20 causes a partial andautomatic closing of space 5 so as to reduce the speed of the diffusedair. A block 19 can be used as a stop to limit the closing of this spaceso that the air always circulates there.

[0047]FIG. 9 represents a means that makes it possible to actuate therotation of strip 20 around joint 18. This means comprises reservoirs 23that contain wax, liquid or saturating vapor, so-called bulbs forexpansion of wax or liquid or a saturating vapor, that canadvantageously replace the electromagnets that are mentioned above. Saidbulbs comprise, in effect, in their upper portion, a piston 24 or anelastic membrane or a bellows that actuates the rotation of strip 20 incase of an increase in temperature that causes the expansion of wax orliquid or the evaporation of a fluid that is located in said bulbs.

[0048]FIG. 10 shows a means that makes it possible to actuate therotation of strip 20 around joint 18. This means comprises U-shapedbimetallic strips 25 that comprise two long wings 26 and 27, consistingof two materials with very different expansion coefficients that areintegral with one another over their entire surface, gripped at regularintervals in slots 28 and 29 that are provided for this purpose in blade11 of strip 20 and in wing 12 of rail 6. Said bimetallic strips areproduced such that of the two materials of which they are constituted,the one that has the highest expansion coefficient under the effect ofan increase in temperature is located on the outside face of U 25. Thedifferential expansion of the two materials that constitute thebimetallic strip causes the two ends of wings 28 and 29 to move towardone another, in the case of an increase in the temperature of the airabove the false ceiling. This drawing-together causes a rotation ofclosing strip 20 around joint 18 and thus a partial closing of space 5.

[0049] In the embodiment according to FIG. 11, the means that makespossible a variable closing of space 5 comprises an undulating shape 30that ends on the side of the wall by a rounded shape 31, whose endpenetrates space 5 and is attached by its other end to end 32 ofhorizontal wing 12, whereby said section 30 is, on its upper face,covered and integral with a sheet 34 that consists of a material thathas a lower thermal expansion coefficient than the one of the materialthat constitutes section 30. Thus, under the effect of an increase intemperature in the volume above the false ceiling, the differentialexpansion of the two materials that constitute section 30 and sheet 34causes rounded shape 31 to move toward the wall and therefore causes apartial closing of opening 5, a closing that is limited by the blocksthat are located above the crosspieces.

[0050] Relative to a traditional air-conditioning by blowing treated airin the upper part of the building, the device according to the inventionrequires, if the last embodiment described above is used, the placementof a single section, the placement of rods 7 at carefully selectedlocations and then the placement of the false ceiling.

[0051] By way of nonlimiting example, the device according to theinvention is particularly intended for the comfortable air-conditioningof buildings such as:

[0052] Apartments and houses,

[0053] Commercial buildings such as banks, stores, pharmacies,

[0054] Medical and dental offices,

[0055] Exhibition halls, with the exception of halls of great height,

[0056] Offices and computer rooms,

[0057] Hotel and hospital rooms,

[0058] Schools and universities.

[0059] Of course, the invention is not limited to the embodimentdescribed and shown in the accompanying drawings. Modifications arepossible, in particular from the viewpoint of the constitution ofvarious elements or by substitution of equivalent techniques, withoutthereby exceeding the field of protection of the invention.

1. Building with an air-conditioning device that comprises a means forintroducing treated air in a volume above a false ceiling (2) and thatensures a diffusion of air along the walls by allowing treated air toenter in a volume created by the space between ceiling (1), sealed falseceiling (2) and walls (3), comprising crosspieces (4) between wall (3)and edge rail (6) of false ceiling (2), of a small width parallel to thewall and evenly spaced, whereby said crosspieces (4), attached to wall(3) or to edge rail (6) of false ceiling (2), reserve a space betweenwall (3) and false ceiling (2) so as to allow the diffusion of air overthe entire periphery of the building, characterized in that it isequipped, in predetermined zones, with one or several rods (7) that aregripped between rail (6) and wall (3) so as to close the space in thezones where it is desired to block the diffusion of the air.
 2. Deviceaccording to claim 1, wherein rod or rods (7) that are gripped betweenrail (6) and wall (3) are full rods.
 3. Device according to claim 1,wherein rod or rods (7) that are gripped between rail (6) and wall (3)are rods that are pierced with orifices such as holes or slots. 4.Device according to claim 1, wherein edge rail (6) of the false ceilingcomprises in its upper portion a rounded shape (8), whereby on its upperwall-side ridge (15), the center of the curvature of this rounded shapeis oriented toward the interior of the building.
 5. Device, according toclaim 1, wherein a rod (9), whose thickness perpendicular to wall (3) isless than the distance between wall (3) and wall-side face (35) of thecore of rail (6), is gripped in space (5) between rail (6) and wall (3)over the entire periphery or over a portion of the periphery of thebuilding.
 6. Device according to claim 1, wherein rail (6) is providedwith a means that makes possible a variable closing of space (5). 7.Device according to claim 6, wherein the means that allows a variableclosing of space (5) comprises, on the one hand, a horizontal wing (12)that is integral with rail (6) on its upper part, and, on the otherhand, a strip (20) that consists of a blade (11), parallel to upper wing(12) of edge rail (6) and above, extended beside the wall by a roundedshape (13), whose center of the curvature is oriented toward theinterior of the building, whereby end (14) of the rounded shape on theside of the wall penetrates space (5) above crosspieces (4) by restingon upper ridge (15) on the side of the wall of rail (6), exhibiting an Lshape (33) that produces a closed box between curved part (13) and blade(11), whereby said strip (20) is linked to upper wing (12) of rail (6)by a vertical blade (16) that is located closer to building-side end(17) than ridge (15), whereby said means allows a variable closing ofspace (5) that also comprises a means that makes it possible to actuatethe rotation of strip (20) around a joint (18).
 8. Device according toclaim 7, wherein springs (21) are placed at regular intervals betweenblade (11) of strip (20) and wing (12) of rail (6) beside its end (17),keeping strip (20) abutting against stop (15) of rail (6).
 9. Deviceaccording to claim 7, wherein the means that makes it possible toactuate the rotation of strip (20) around joint (18) consists ofelectromagnets (22), evenly spaced and controlled at a distance, eitherby a circuit breaker or by slaving at a predetermined temperature in acertain location and at a certain level in a building.
 10. Deviceaccording to claim 7, wherein the means that makes it possible toactuate the rotation of strip (20) around joint (18) consists ofreservoirs (23) that contain wax, liquid or saturating vapor, so-calledexpansion bulbs of wax or liquid or saturating vapor, evenly spaced,whereby in their upper part, said bulbs comprise a piston (24) or anelastic membrane or a bellows that actuates the rotation of strip (20)around joint (18) in case of an increase in temperature, causing theexpansion of the wax or of the liquid or the evaporation of a fluid thatis located in said bulbs.
 11. Device according to claim 7, wherein themeans that makes it possible to actuate the rotation of strip (20)around joint (18) consists of U-shaped bimetallic strips (25) thatcomprise two long wings (26) and (27), consisting of two materials withdifferent expansion coefficients, whereby said bimetallic strips aregripped at regular intervals in slots (28) and (29) that are providedfor this purpose in blade (11) of strip (20) and in wing (12) of rail(6).
 12. Device according to claim 6, wherein the means that makespossible a variable closing of space (5) comprises a corrugated section(30) that ends on the side of the wall by a rounded shape (31), whoseend penetrates space (5) and is attached by its other end to end (32) ofhorizontal wing (12), whereby said section (30) is, on its upper face,covered and integral with a sheet (34) that consists of a material thathas a lower thermal expansion coefficient than the one of the materialthat constitutes section (30).